London, 1670. The completion of his new project could not have run more smoothly for Christopher Redmayne. Commissioned to design a new house for Francis Polegate, a merchant, Christopher is pleased that everything has gone without a hitch. To celebrate the success of the venture, Polegate throws a party and invites Christopher as an honoured guest. Also invited are Susan Cheever, Christopher's sweetheart, her father, Sir Julius Cheever MP, and Bernard Everett, Polegate's brother-in-law. But the party comes to an abrupt end when one of the guests is murdered upon leaving the house...With blood staining the doorstep of his new creation, Christopher can't help but feel involved. With the help of his good friend, the Puritan Constable Jonathan Bale, and his dissolute brother, Henry, Christopher vows to find the killer and bring him to justice. However, preliminary investigations suggest that the victim was a well-liked man with no known enemies. Could it therefore have been a case of mistaken identity? In which case, just who was the intended target?